Humoral and cellular immune capabilities of MS patients and matched controls have been studied. Initial studies indicate that the immune system of MS patients is not significantly different from that of controls. A specific antibody and a diagnostic complement fixation test for simian hemorrhagic fever has been developed. Solid phase radioimmunological tests are underway to identify the antigens associated with measles and herpes, CMV and EB viruses. Efforts are being made to produce specific antisera and to utilize the specific antigens and antibody for identification and classification of viral agents.